Process for homogeneously polymerized high unsaturation C4-C10 isoolefin conjugated diene copolymers

Abstract

A homogeneous polymerization process for preparing high unsaturation, high number average molecular weight polymers of isoolefins and conjugated multiolefins, particularly cyclic conjugated multiolefins, by use of a blend of at least one solvent selected from the C 4 -C 8 acyclic paraffins such as hexane with at least one solvent selected from the C 5 -C 8 cycloparaffins such as cyclohexane.

What is claimed is: 
     
       1. In a solution polymerization process for preparing a substantially gel-free, high number average molecular weight, high unsaturation copolymer of a C 4  -C 10  isoolefin and at least one C 5  -C 9  cyclic conjugated multiolefin wherein said copolymer contains about 5 to about 40 mole percent unsaturation and wherein the polymerization is performed by using as a catalyst a catalytic amount of either an aluminum halide dissolved in a polar solvent or a hydrocarbyl aluminum dihalide and wherein the polymerization is carried out at a temperature below -100° C., the improvement which comprises using a cosolvent in the amount of about 20 to about 40 volume percent based on the monomers plus cosolvent wherein the cosolvent comprises a blend of about 15 to about 90 volume percent of at least one C 5  -C 8  cycloparaffin and about 85 to about 10 volume percent of at least one C 4  -C 8  acyclic paraffin based on the total volume of cosolvent. 
     
     
       2. The process of claim 1 wherein the isoolefin is isobutylene. 
     
     
       3. The process of claim 1 wherein the multiolefin is cyclopentadiene. 
     
     
       4. The process of claim 1 wherein the polymer unsaturation is about 6 to about 35 mole %. 
     
     
       5. The process of claim 1 wherein the M n  is at least 120,000. 
     
     
       6. The process of claim 1 wherein the C 5  -C 8  cycloparaffin is selected from the group consisting of cyclopentane, methyl cyclopentane, cyclohexane, methyl cyclohexane, and dimethyl cyclohexane. 
     
     
       7. The process of claim 1 wherein the C 5  -C 8  cycloparaffin is cyclohexane. 
     
     
       8. The process of claim 1 wherein the C 4  -C 8  acyclic paraffin is selected from the group consisting of butane, pentane, hexane, heptane and octane. 
     
     
       9. The process of claim 1 wherein the C 4  -C 8  acyclic paraffin is commercial hexane. 
     
     
       10. The process of claim 1 wherein the cycloparaffin is used at about 25 to about 75 volume percent and the acyclic paraffin is used at about 75 to about 25 volume percent based on the total volume of cosolvent. 
     
     
       11. The process of claim 1 wherein the cycloparaffin is used at about 25 to about 40 volume percent and the acyclic paraffin is used at about 75 to about 60 volume percent based on the total volume of cosolvent. 
     
     
       12. In a solution polymerization process for preparing a substantially gel-free, high number average molecular weight, high unsaturation copolymer of a C 4  -C 10  isoolefin, at least one C 5  -C 14  acyclic conjugated diolefin and at least one C 5  -C 9  cyclic conjugated multiolefin wherein said copolymer contains about 5 to about 40 mole percent unsaturation and wherein the polymerization is performed by using as a catalyst a catalytic amount of either an aluminum halide dissolved in a polar solvent or a hydrocarbyl aluminum dihalide and wherein the polymerization is carried out at a temperature below -100° C., the improvement which comprises using a cosolvent in the amount of about 20 to about 40 volume percent based on the monomers plus cosolvent wherein the cosolvent comprises a blend of about 15 to about 90 volume percent of at least one C 5  -C 8  cycloparaffin and about 85 to about 10 volume percent of at least one C 4  -C 8  acyclic paraffin based on the total volume of cosolvent. 
     
     
       13. The process of claim 12 wherein the isoolefin is isobutylene. 
     
     
       14. The process of claim 12 wherein the acyclic conjugated diolefin is selected from the group consisting of isoprene, piperylene, 2,3-dimethyl butadiene and 2,5-dimethyl hexadi, 2,4-ene. 
     
     
       15. The process of claim 13 wherein the acyclic conjugated diolefin is isoprene. 
     
     
       16. The process of claim 12 wherein the cyclic conjugated multiolefin is selected from the group consisting of cyclopentadiene, methylcyclopentadiene, cyclohexadiene, and fulvene. 
     
     
       17. The process of claim 15 wherein the cyclic conjugated multiolefin is cyclopentadiene. 
     
     
       18. The process of claim 12 wherein the cyclic conjugated diolefin is cyclopentadiene. 
     
     
       19. The process of claim 12 wherein the polymer unsaturation is about 6 to about 35 mole %. 
     
     
       20. The process of claim 12 wherein the M n  is at least 120,000. 
     
     
       21. The process of claim 12 wherein the C 5  -C 8  cycloparaffin is selected from the group consisting of cyclopentane, methyl cyclopentane, cyclohexane, methylcyclohexane, and dimethylcyclohexane. 
     
     
       22. The process of claim 12 wherein the C 5  -C 8  cycloparaffin is cyclohexane. 
     
     
       23. The process of claim 12 wherein the C 4  -C 8  acyclic paraffin is selected from the group consisting of butane, pentane, hexane, heptane and octane. 
     
     
       24. The process of claim 12 wherein the C 4  -C 8  acyclic paraffin is commercial hexane. 
     
     
       25. In a solution polymerization process for preparing a substantially gel-free, high number average molecular weight, high unsaturation copolymer of a C 4  -C 10  isoolefin and cyclopentadiene wherein said copolymer contains about 5 to 40 mole percent unsaturation and wherein the polymerization is carried out in a homogeneous phase using as a catalyst a catalytic amount of either an aluminum halide dissolved in a polar solvent or a hydrocarbyl aluminum dihalide and wherein the polymerization temperature is below -100° C., the improvement which comprises using about 20 to about 40 volume % of cosolvent based on the cosolvent plus monomers wherein the cosolvent comprises about 15 to about 90 volume % of at least one C 5  -C 8  cycloparaffin and about 85 to about 10 volume % of at least one C 4  -C 8  acyclic paraffin based on the total volume of cosolvent. 
     
     
       26. The process of claim 25 wherein the cycloparaffin is used at about 25 to about 40 volume % and the acyclic paraffin is used at about 75 to about 60 volume % based on the total volume of cosolvent. 
     
     
       27. The process of claim 25 wherein the cycloparaffin is cyclohexane and the acyclic paraffin is commercial hexane. 
     
     
       28. The process of claim 25 wherein the isoolefin is isobutylene. 
     
     
       29. The process of claim 25 wherein the C 5  -C 8  cycloparaffin is selected from the group consisting of cyclopentane, methylcyclopentane, methylcyclohexane and dimethylcyclohexane. 
     
     
       30. The process of claim 25 wherein the C 5  -C 8  cycloparaffin is cyclohexane. 
     
     
       31. The process of claim 25 wherein the C 4  -C 8  acyclic paraffin is selected from the group consisting of butane, pentane, heptane and octane. 
     
     
       32. The process of claim 25 wherein the C 4  -C 8  acyclic paraffin is commercial hexane. 
     
     
       33. The process of claim 1 wherein the polar solvent is a halogenated aliphatic hydrocarbon. 
     
     
       34. The process of claim 12 wherein the polar solvent is a halogenated aliphatic hydrocarbon. 
     
     
       35. The process of claim 25 wherein the polar solvent is a halogenated aliphatic hydrocarbon. 
     
     
       36. The process of claim 33 wherein the halogenated hydrocarbon is a C 1  to C 4  chlorinated hydrocarbon. 
     
     
       37. The process of claim 34 wherein the halogenated hydrocarbon is a C 1  to C 4  chlorinated hydrocarbon. 
     
     
       38. The process of claim 35 wherein the halogenated hydrocarbon is a C 1  to C 4  chlorinated hydrocarbon. 
     
     
       39. The process of claim 1 wherein the aluminum halide is aluminum chloride. 
     
     
       40. The process of claim 12 wherein the aluminum halide is aluminum chloride. 
     
     
       41. The process of claim 25 wherein the aluminum halide is aluminum chloride. 
     
     
       42. The process of claim 1 wherein the polymerization temperature is about -110° C. to -135° C. 
     
     
       43. The process of claim 12 wherein the polymerization temperature is about -110° C. to -135° C. 
     
     
       44. The process of claim 25 wherein the polymerization temperature is about -110° C. to -135° C. 
     
     
       45. The process of claim 1 wherein the multiolefin is selected from the group consisting of cyclopentadiene, methylcyclopentadiene, cyclohexadiene, and fulvene. 
     
     
       46. The process of claim 1 wherein the hydrocarbyl aluminum dihalide is a hydrocarbyl aluminum dibromide or a dichloride. 
     
     
       47. The process of claim 12 wherein the hydrocarbyl aluminum dihalide is a hydrocarbyl aluminum dibromide or a dichloride. 
     
     
       48. The process of claim 25 wherein the hydrocarbyl aluminum dihalide is a hydrocarbyl aluminum dibromide or dichloride. 
     
     
       49. The process of claim 1 wherein the hydrocarbyl aluminum dihalide is selected from the group consisting of ethyl aluminum dichloride, isobutyl aluminum dichloride or methyl aluminum dichloride. 
     
     
       50. The process of claim 12 wherein the hydrocarbyl aluminum dihalide is selected from the group consisting of ethyl aluminum dichloride, isobutyl aluminum dichloride or methyl aluminum dichloride. 
     
     
       51. The process of claim 25 wherein the hydrocarbyl aluminum dihalide is selected from the group consisting of ethyl aluminum dichloride, isobutyl aluminum dichloride or methyl aluminum dichloride.